Chain guide assembly with movable member

ABSTRACT

A bicycle chain guide assembly that includes a mounting bracket adapted to be affixed to a bicycle, and a movable member movably mounted to the mounting bracket. The movable member includes a chain guide portion adapted to be positioned adjacent a chain ring of the bicycle and below a bottom bracket of the bicycle. When the assembly is mounted on a bicycle with a chain-ring, the movable member can move in a first direction such that the chain guide portion moves toward an outer circumference of the chain-ring and the movable member can move in a second direction such that the chain guide portion moves away from the outer circumference of the chain ring.

FIELD OF THE INVENTION

The present invention relates to a chain guide assembly for a bicycle.

BACKGROUND OF THE INVENTION

Currently, chain guide assemblies such as shown in U.S. Pat. No.6,533,690, which is incorporated by reference herein in its entirety,are typically installed on bicycles that encounter bumpy situations andare used to keep the chain on the chain ring of the front drive train.However, a more stable, lightweight and quieter chain guide assembly isdesired. The invention described herein addresses these issues.

SUMMARY OF THE PREFERRED EMBODIMENTS

in accordance with a first aspect of the present invention there isprovided a bicycle chain guide assembly that includes a chain guidemember having a mounting portion adapted to be positioned adjacent achain ring of a bicycle, and a contact member removably affixed to themounting portion. The mounting portion extends in a chain-runningdirection and has a chain-ring side and an opposite side. The contactmember includes a first end portion affixed to the mounting portion anda chain contact portion that extends from the first end portion in thechain-running direction and is positioned adjacent the chain-ring sideof the mounting portion. A gap is defined between the chain-ring side ofthe mounting portion and the chain contact portion of the contactmember. In a preferred embodiment, the contact member is made of aresilient material such that it can be deflected and the contact memberis positioned on the mounting portion by sliding the contact member in asliding direction that is perpendicular to the chain-running direction.In a preferred embodiment, when the assembly is mounted on a bicycle,the chain-ring side of the mounting portion has a first curvatureprotruding toward the chain-ring and the chain contact portion of thecontact member has a second curvature protruding toward the chain-ring.The first curvature and the second curvature are selected such that thegap is defined therebetween. The chain guide member includescircumferentially arranged slots for adjustable attachment to a bicyclebottom bracket.

In accordance with another aspect of the present invention, there isprovided a bicycle chain guide assembly that includes a mounting bracketadapted to be affixed to a bicycle, and a movable member movably mountedto the mounting bracket. The movable member includes a chain guideportion adapted to be positioned adjacent a chain ring of the bicycleand below a bottom bracket of the bicycle. When the assembly is mountedon a bicycle with a chain-ring, the movable member can move in a firstdirection such that the chain guide portion moves toward an outercircumference of the chain-ring and the movable member can move in asecond direction such that the chain guide portion moves away from theouter circumference of the chain ring. Preferably, the assembly includesfirst and second limit constructions that include a pin provided on themounting bracket and a slot provided on the movable member that receivesthe pin. In another embodiment, the movable member is movably mounted tothe mounting bracket such that it moves upwardly and downwardly viaslots defined therein.

The invention, together with additional features and advantages thereof,may be best understood by reference to the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a chain guide assembly affixed to thebottom bracket of a bicycle in accordance with a first preferredembodiment of the present invention;

FIG. 2 is an exploded view of the chain guide assembly of FIG. 1;

FIG. 3 is a right side elevational view of the chain guide assembly ofFIG. 1;

FIG. 4 is a rear elevational view of the chain guide assembly of FIG. 1;

FIG. 5 is a right side elevational view of the chain guide assembly ofFIG. 1 with the chain-ring omitted and the movable member in solid anddashed lines to show its pivotal action;

FIG. 6 is a left side elevational view of chain guide assembly of FIG. 1with the movable member in solid and dashed lines to show its pivotalaction;

FIG. 7 is a detailed view of the chain guide portion including an insertmember in accordance with a preferred embodiment of the presentinvention;

FIG. 8 is a right side elevational view of a chain guide assemblyaffixed to the bottom bracket of a bicycle in accordance with anotherpreferred embodiment of the present invention; and

FIG. 9 is a right side elevational view of a chain guide assemblyaffixed to the bottom bracket of a bicycle in accordance with yetanother preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description and drawings are illustrative and are not tobe construed as limiting. Numerous specific details are described toprovide a thorough understanding of the disclosure. However, in certaininstances, well-known or conventional details are not described in orderto avoid obscuring the description. References to one or an embodimentin the present disclosure can be, but not necessarily are references tothe same embodiment; and, such references mean at least one of theembodiments.

Reference in this specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the-disclosure. The appearances of the phrase “in one embodiment” invarious places in the specification are not necessarily all referring tothe same embodiment, nor are separate or alternative embodimentsmutually exclusive of other embodiments. Moreover, various features aredescribed which may be exhibited by some embodiments and not by others.Similarly, various requirements are described which may be requirementsfor some embodiments but not other embodiments.

It will be appreciated that terms such as “front,” “back,” “top,”“bottom,” “side,” “short,” “long,” “up,” “down,” and “below” used hereinare merely for ease of description and refer to the orientation of thecomponents as shown in the figures. It should be understood that anyorientation of the components described herein is within the scope ofthe present invention.

Referring now to the drawings, wherein the showings are for purposes ofillustrating the present invention and not for purposes of limiting thesame, FIGS. 1-7 show a chain guide assembly 10 for a bicycle thatgenerally includes a mounting bracket 12, and movable member 14 togetherwith a chain guide portion 31. In a preferred embodiment, the chainguide assembly 10 is mounted on the bottom bracket 100 of a bicycle.However, this is not a limitation on the present invention, and thechain guide assembly can be affixed to or mounted on other parts of abicycle.

As shown in FIG. 2, a bottom bracket 100 includes bosses 102 to whichthe mounting bracket 12 is adapted to be affixed. In a preferredembodiment, the mounting bracket has a generally circular shape with acenter opening 16 through which a crank can extend, along with threecircumferentially arranged slots 18 for mounting the mounting bracket 12to the bosses 102 via threaded fasteners or the like. As will beappreciated by those skilled in the art, the slots 18 allow foradjustability. In another embodiment, the slots can be replaced bycircular openings that align with the bosses 102. The mounting bracket12 preferably includes bosses 20 and 22 that have openings 24 and 26therein for mounting the movable member 14 thereto, as described below.As shown in FIG. 2, in a preferred embodiment, mounting bracket 12includes more than one (three are shown) opening 26. This providesadjustability as described below. In another embodiment, only oneopening 26 is provided.

As is shown in FIG. 2, in a preferred embodiment, the movable member 14includes a lower portion 28, an upper portion 30 that is divided intofirst and second halves 30 a and 30 b with a gap 30 c definedtherebetween, and a mounting member 62 (which is part of the chain guideportion 31). The movable member 14 also includes openings 32 a and 32 band slots 34 a and 34 b defined in first and second halves 30 a and 30 bof the upper portion 30. The openings and slots are referred to hereinboth separately as openings 32 a and 32 b, slots 34 a and 34 b andtogether as an opening 32 and a slot 34.

To mount the movable member 14 to the mounting bracket 12, bosses 20 and22 are received in slot 30 c such that openings 32 a and 32 b arealigned with opening 24 and slots 34 a and 34 b are aligned with atleast one of the openings 26. Pins or the like are inserted through thealigned openings and slots to secure the movable member 14 to themounting bracket 12. It will be understood that any type of pin,threaded fastener, rivet or other component known in the art can be usedto secure the movable member 14 to the mounting bracket 12. This is nota limitation on the present invention. In the figures, openings 32 a and32 b and opening 24 receive a nut 36, spacer 38, sleeve 40, bolt 42,washer 44 and biasing member 46 (described below and mounted on sleeve40) and slots 34 a and 34 b and openings 26 receive a nut 48 and bolt 50to movably mount the movable member 14 to the mounting bracket 12. In analternative embodiment, one of the two halves 30 a and 30 b be omitted.It will understood that when the mounting bracket 12 and movable member14 are mounted on a bicycle, the chain guide portion 31 will bepositioned adjacent an outer most chain-ring 104 of a plurality of chainrings (or a single chain-ring 104 on bicycles with only one chain-ring104).

It will be appreciated by those skilled in the art, that in theconfiguration described above, nut 36, spacer 38, sleeve 40, and bolt 42define a pivot axis about which the movable member 14 can pivot, swingor move and nut 48 and bolt 50 move up and down within slots 34 a and 34b as the movable member pivots about the pivot axis. As shown by thearrows in FIGS. 5 and 6, the movable member 14 can move in a firstdirection such that the chain guide portion 31 moves toward thechain-ring 104 and in a second direction such that the chain guideportion 31 moves away from the chain ring 14. In its simplest form, theassembly 10 includes a pin (called a first pin or pivot assembly herein)that defines a pivot axis about which the movable member 14 can pivot,and a pin (called a second pin or sliding assembly herein) that movesupwardly and downwardly and is bounded by the two ends of the slot(s),which are referred to herein as the upper limit 52 and the lower limit54. FIGS. 5 and 6 show the movable member 14 in both dashed and solidlines. The solid lines represent the movable member 14 in the normalposition where it is biased downwardly and at the lower limit (with bolt50 and nut 48 at the lower limit 54 of slot 34). The dashed linesrepresent the movable member 14 in the action position (e.g., afterbeing hit by a tree stump) where it is moved upwardly and at the upperlimit (with bolt 50 and nut 48 at the upper limit 52 of slot 34). Inanother embodiment, the pin and slot arrangement can be reversed suchthat the slot is defined in mounting bracket 12 and the pin or the likeextends from the movable member 14.

It will be understood that other constructions for limiting the movementof the movable member 14 in the first and second directions are withinthe scope of the present invention. For example, the assembly 10 caninclude stoppers or abutments affixed to the mounting bracket 12, thatare positioned above and below the movable member 14 and that limit itsmovement.

As discussed above, the pivot assembly includes a biasing member 46 orspring coaxially disposed about the pivot assembly (and, thereby, thepivot axis). The biasing member 46 includes a first end portion 46 athat contacts the mounting bracket 12 and a second end portion 46 b thatcontacts the movable member 14. In a preferred embodiment, the mountingbracket includes a pin or bolt 56 that is threaded into or otherwiseattached thereto or formed therewith. As is shown in FIG. 6, the firstend portion 46 a of the biasing member 46 contacts the bolt 56. In apreferred embodiment, the bolt 56 is threaded into an opening 58 in themounting bracket 12. Preferably, the mounting bracket 12 includes morethan one opening 58 defined therein (three are shown). This providesadjustability. However, this is not a limitation on the presentinvention. In a preferred embodiment, the movable member 14 includes apin 60 secured thereto, which is contacted by the second end 46 b of thebiasing member 46. As shown in FIG. 6, pin 60 is a unitary part ofmovable member 14. However, this is not a limitation on the presentinvention and pin 60 could be threaded or otherwise attached to movablemember 14.

It will be appreciated that the first and second ends 46 a and 46 b ofthe biasing member 46 contacting bolt 56 and pin 60 biases movablemember 14 downwardly, and, when mounted on a bicycle, away fromchain-ring 104 (the second direction, as described above). Therefore, inthe normal position, the chain guide portion 31 is biased downwardly andthe sliding assembly/pin is positioned at the lower limit 54 of slot 34.When the chain guide portion 31 or any part of the movable member 11 isstruck by an object, such as a tree, rock, mound, etc., the movablemember 14 pivots upwardly (in the first direction) as much as necessaryunless the sliding assembly/pin reaches the upper limit 52 of slot 34.This helps protect the drain guide portion 31 from damaging the chain orchain-ring.

As shown in FIGS. 1-7, in a preferred embodiment, the chain guideportion 31 includes a mounting portion 62 that extends outwardly fromthe movable member 14, and a contact member or skid plate 64 and guardmember 68, that are affixed to the mounting portion 62. Generally, thecontact member 64 is positioned on the mounting portion 62 and below thechain and is designed to deflect when contacted by the chain when thebicycle is in use. The mounting portion 62 includes a chain-ring side 62a and an opposite side 62 b (top and bottom, respectively, as shown inFIG. 3). In a preferred embodiment, the contact member 64 includes firstand second end portions 64 a and 64 b with a chain contact portion 64 cextending therebetween. It will be understood that the chain contactportion 64 c generally extends in the direction that the chain runs orextends (the chain-running direction). Preferably, the mounting portion62 includes first and second seats 62 c and 62 d that receive at least aportion of the first and second end portions 64 a and 64 b of thecontact member 64. In a preferred embodiment, the contact member 64 isslid onto the mounting portion 62 in a direction substantiallyperpendicular to the chain-running direction. However, this is not alimitation. In another embodiment, the contact member 64 can be snap fitonto the mounting portion 62.

As is best shown in FIG. 3, in a preferred embodiment, the upper surfaceor chain-ring fixing side of the mounting portion 62 a has a firstcurvature protruding toward the chain-ring and the chain contact portion64 c of the contact member 64 has a second curvature protruding towardthe chain-ring. The first curvature and the second curvature areselected such that a gap 66 is defined therebetween. Preferably, thecurvatures are convex. However, they may both be concave or one may beconcave and the other convex or one may be flat and the other convex.Any arrangement that provides a gap therebetween is within the scope ofthe present invention. In use, when the chain contacts the chain contactportion 64 c, the chain contact portion 64 c deflects downwardly,thereby narrowing the gap 66. This action helps prevent damage to thechain and reduces noise. Also, if the contact member 64 becomes worn, auser can replace the contact member 64 with a new one. The contactmember 64 can be made of any resilient material that is flexible enoughto deflect as desired, such as resin or the like. In another embodiment,the contact member 64 and mounting portion 62 can be a unitary piecethat still provides deflection when the contact member 64 is contactedby a chain.

In a preferred embodiment, the chain guide portion 31 also includes aguard member 68 is affixed to the mounting portion 62 by a threadedfastener 70 or the like. At least a portion of the guard member extendstoward the chain ring beyond or above a top surface of the contactmember 64. In a preferred embodiment of the invention, to replace thecontact member 64, a user removes the threaded fastener 70 and guardmember 68, slides off the worn contact ember 64 and slides, a newcontact member 64 and reattaches the threaded fastener 70 and guardmember 68.

The combined action of both the movable member 14 and the deflection ofthe contact member 64 provides protection for the chain and thechain-ring.

As shown in FIG. 7, in another embodiment, the chain guide portion 31can include an insert member disposed in the gap 66 between the mountingportion 62 and the contact member 64. The insert member 72 is preferablymade of rubber or other resilient material and provides cushion orfurther resilience when the chain contacts the contact member 64. Asshown in FIG. 7, in a preferred embodiment, the insert member 72 dividesgap 66 into first and second spaces 74 a and 74 b. This provides roomfor insert member 72 to deflect when compressed. In another embodiment,insert member 72 can completely fill gap 66.

As shown in FIG. 8, in another embodiment of a chain guide assembly 76the chain guide portion 31 can extend from a mounting bracket or chainguide member 71 that is affixed to the bicycle and positions the chainguide portion 31, including the contact member 64 adjacent to thechain-ring 104 and chain. This embodiment essentially eliminates themovable member 14.

As shown in FIG. 9, in an alternative embodiment, the movable member 14can include two slots 34 instead of a slot and opening combination. Itwill be understood that with this construction, the entire movablemember 14 moves upwardly and downwardly instead of pivoting upwardly anddownwardly about a pivot axis. In this embodiment, the movable member 14is biased downwardly. Any number of configurations can be used to biasthe movable member 14 downwardly. For example, each pin or bolt 50within the slots 34 can include a biasing member similar to biasingmember 46 above. Or, a single biasing member or coil spring can be usedto bias the entire movable member 14 downwardly. Any configuration wherethe movable member 14 has an upper limit construction and a lower limitconstruction is within the scope of the invention. FIG. 9 shows themovable member in solid lines in the action position and in dashed linesin the normal position.

Those of skill in the art will appreciate from a review of thedescription and drawings herein, that the chain guide assembliesdisclosed herein supply a degree of adjustability, by providing, e.g.,slots 18 so the mounting bracket 12 or chain guide member 71 can berotated or more than one opening 26 or 58 for repositioning bolts 50 and56. Other adjustment possibilities will be readily apparent to those ofskill in the art.

It will be understood that there are essentially two different inventiondisclosed herein, the up and down movement of the movable member and thedeflectable action of the contact member. Both of these can be combinedinto one chain guide assembly, or they can be implemented separately. Inan embodiment, where the contacted member is omitted, the chain guideportion can simply include a surface on which the chain can slide ifcontacted (without any deflection) or a small chain ring or the like.

While certain aspects of the disclosure are presented below in certainclaim forms, the inventors contemplate the various aspects of thedisclosure in any number of claim forms. For example, while only oneaspect of the disclosure is recited as a means-plus-function claim under35 U.S.C. §112, ¶6, other aspects may likewise be embodied as ameans-plus-function claim, or in other forms, such as being embodied ina computer-readable medium. (Any claims intended to be treated under 35U.S.C. §112, ¶6 will begin with the words “means for”). Accordingly, theapplicant reserves the right to add additional claims after filing theapplication to pursue such additional claim forms for other aspects ofthe disclosure.

Accordingly, although exemplary embodiments of the invention have beenshown and described, it is to be understood that all the terms usedherein are descriptive rather than limiting, and that many changes,modifications, and substitutions may be made by one having ordinaryskill in the art without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A bicycle chain guide assembly comprising: amounting bracket adapted to be affixed to a bicycle with at least onechain ring, a movable member pivotably mounted to the mounting bracketby at least a first pin that defines a pivot axis, wherein the movablemember includes a chain guide portion adapted to be positioned adjacentthe front chain ring of the bicycle and below a bottom bracket of thebicycle, the bottom bracket being configured to receive a crank, andwherein when the assembly is mounted, the movable member can pivot aboutthe pivot axis such that the chain guide portion can move in a firstdirection toward an outer circumference of the front chain ring and in asecond direction away from the outer circumference of the front chainring, a first limit construction to limit movement of the movable memberin the first direction, a second limit construction to limit movement ofthe movable member in the second direction, wherein the first and secondlimit constructions comprise a second pin and a slot that receives thesecond pin, the second pin being provided on one of the mounting bracketand the movable member and the slot being provided on the other of themounting bracket and the movable member, and a biasing member thatbiases the movable member in the second direction.
 2. The bicycle chainguide assembly of claim l wherein the movable member further includes aguard member attached to the chain guide portion, wherein when theassembly is mounted on a bicycle, the guard member extends from thechain guide portion toward the front chain ring.
 3. The bicycle chainguide assembly of claim 1 wherein the mounting bracket includes a centeropening, wherein the mounting bracket is configured to be affixed to thebottom bracket of the bicycle such that a crank extends through thecenter opening of the mounting bracket.
 4. The bicycle chain guideassembly of claim 1 wherein the mounting bracket is adjustably affixedto the bicycle.
 5. The bicycle chain guide assembly of claim 1 whereinwhen the assembly is mounted on a bicycle, the chain guide portion ispositioned adjacent an outer most front chain-ring of a plurality ofchain rings.
 6. The bicycle chain guide assembly of claim 1 wherein thechain guide portion is disposed on the movable member at a point that isremote from the first pin.
 7. The bicycle chain guide assembly of claim1 wherein the chain guide portion moves in an arcuate path when themovable member pivots about the pivot axis.
 8. A bicycle chain guideassembly comprising: a mounting bracket adapted to be affixed to abicycle with at least one chain ring, a movable member pivotably mountedto the mounting bracket by at least a first pin that defines a pivotaxis, wherein the movable member includes a chain guide portion adaptedto be positioned adjacent the chain ring of the bicycle, and whereinwhen the assembly is mounted, the movable member can pivot about thepivot axis such that the chain guide portion can move in a firstdirection toward an outer circumference of the chain-ring and in asecond direction away from the outer circumference of the chain ring, afirst limit construction to limit movement of the movable member in thefirst direction, a second limit construction to limit movement of themovable member in the second direction, wherein the first and secondlimit constructions comprise a second pin provided on the mountingbracket and a slot provided on the movable member that receives thesecond pin, and a biasing member that biases the movable member in thesecond direction, wherein the biasing member includes a first endportion and second end portion, wherein the first end portion contactsthe mounting bracket and the second end portion contacts the movablemember.
 9. The bicycle chain guide assembly of claim 8 wherein thebiasing member is coaxially disposed about the pivot axis.
 10. A bicyclechain guide assembly comprising: a mounting bracket adapted to beaffixed to a bicycle with at least one front chain ring, a movablemember pivotably mounted to the mounting bracket by at least a first pinthat defines a pivot axis, wherein the movable member includes a chainguide portion adapted to be positioned adjacent the front chain ring ofthe bicycle and below a bottom bracket of the bicycle, and wherein whenthe assembly is mounted, the movable member can pivot about the pivotaxis such that the chain guide portion can move in a first directiontoward an outer circumference of the front chain ring and in a seconddirection away from the outer circumference of the front chain ring,wherein the chain guide portion includes a mounting portion that extendsin a chain-running direction, and wherein the mounting portion has achain-ring side and an opposite side, and a contact member removablyaffixed to the mounting portion, wherein the contact member includes afirst end portion affixed to the mounting portion and a chain contactportion that extends from the first end portion in the chain-runningdirection and is positioned adjacent the chain-ring side of the mountingportion, wherein a gap is defined between the chain-ring side of themounting portion and the chain contact portion of the contact member.11. The bicycle chain guide assembly of claim 10 wherein the contactmember is made of a resilient material such that it can be deflected toat least partially narrow the gap.